The great pest plant hunt - can you help us?

We are on the hunt for sightings of pest plants in our eradication programme(external link). These are pests we are trying to eradicate from the Islands over the duration of the plan, but we need your help.

Can you help us find any of the pests listed below - you may help uncover a new site that our biosecurity staff were unaware of.

We are on the lookout for:

Broom – is known to be present at 13 sites on Chatham Island/Rēkohu/Wharekauri and 1 site on Pitt Island/Rangihaute/Rangiauria.

Description

• Stems are five-angled, green when young, turning woody with age.
• Hairy 15mm leaves are grouped in threes and deciduous.
• Seed pods are hairy and green-brown, maturing to black.
• White broom has white, pea-like flowers and is often marked with a dark pinkish streak near the base.
• Seeds are dispersed by explosive seedpods and contaminated soil on livestock.
• Human-mediated dispersal through movement of contaminated soil on vehicles and machinery.
• Habitats include lowland and montane areas, shrublands, grasslands, steep slopes, open forests, riparian areas, riverbeds, wastelands, disturbed habitats, pastures, and plantations.

Find out more about broom(external link).

Chilean rhubarb – also known as gunnera is known to occur at multiple sites in the south of Chatham Island/Rēkohu/Wharekauri and 1 site on Pitt Island/Rangihaute/Rangiauria.

Description

• The leaves are large (up to 1m wide and 2.5m tall), shiny, and prickly to the touch.
• Leaves die back  to large, creeping stems over winter.
• Flowers are minute, green or pink/red and on large flower spikes up to 1m tall
• Fruits are small and orange
• Birds, water and deliberate plantings disperse seeds. Vegetative spread from rhizome (root) or stem fragments.
• Habitats include coastal and riparian areas, cliffs, wetlands, disturbed sites, slips, and roadsides.

Find out more about Chilean rhubarb(external link).

Wild ginger (kahili ginger) and yellow ginger – is known to be present at only one site on Chatham Island/Rēkohu/Wharekauri (out towards Point Durham) on the SW side of the island. There is no known sites on Pitt Island/Rangihaute/Rangiauria.

Description

• Kahili and yellow ginger are non-woody, ginger scented perennials.
• Yellow ginger produces ream flowers from May-June that do not bear fruit.
• Kahili ginger produces many fragrant lemon-yellow flowers with red stamens from January-March which develop into fleshy orange fruits containing bright scarlet seeds.
• Both varieties can grow up 2 metres tall or more and produce many branching rhizomes which spread outwards to produce a rhizome bed a metre or more deep.
• Kahili ginger also produces up to 100 seeds per flower head, making it a more prolific spreader than yellow ginger.
• Seeds are spread by birds
• Rhizome’s resprout from any fragment and can survive years away form soil, crushing, and immersion in sea.
• They are long-lived and fast-growing, forming dense mats in native forests and other habitats, smothering seedlings, and suppressing indigenous regeneration by up to 90%.

Find out about wild ginger(external link) or yellow ginger(external link).

Wild and yellow ginger. Photo credit: Carolyn Lewis

Be in to win

If you find any of these plants or others listed in our eradication programme, please contact us immediately either by phoning the Council on (03) 305 0033 and ask to speak to the biosecurity team or email info@chathamislands.govt.nz.

Staff will be in contact and will come and check the sites. This is an amazing way for all of us to work together to protect the Island’s biodiversity values.

To encourage people to be on the lookout, we have 4 x $50 warehouse vouchers to be won. Anyone that contacts us with a new site of any pest plant in our eradication programme will be in the draw to win. Winners will be notified towards the end of March.

Broom and Chilean rhubarb photo credit: Trevor James